It is widely recognized that regular physical exercise of the human body is a beneficial and integral part of developing and maintaining a healthy lifestyle. Exercise is useful for weight control, developing muscle tone and strength training. In addition, regular exercise has been shown to be an effective way of maintaining and improving an individual's cardiovascular health. Further, regular physical exercise has proven to be an important means of combating and reducing excess stress and stress-related physical ailments such as hypertension and fatigue. Additionally, repetitive exercise is commonly prescribed to patients suffering various injuries where it performs an important role in rehabilitation.
Depending on specific patient needs and injuries, as well as the type of tissue targeted, physical therapists have at their disposal many exercise options. For example, in order to develop or rehabilitate muscle tissue, an exercise regimen combining relatively heavy resistance with fewer repetitions, such as weight training, is often advantageous. In contrast, some tissues including ligaments, cartilage and tendons are frequently rehabilitated more effectively with targeted exercises that employ lower resistance with a comparatively greater number of repetitions.
In order to supply injured tissue with the oxygen that research has shown to be necessary to properly develop, strengthen and rehabilitate injured tissue, repetitive aerobic exercise is often prescribed. Since connective tissues such as ligaments, cartilage, and tendons require a greater amount of oxygen during rehabilitative exercise than muscle tissue, and because injuries to the lumbar spine often involve these connective tissues, many low back injuries are effectively treated by a rehabilitative program including a low resistance, high repetition exercise regimen.
Over the last several years, numerous aerobic exercise options have become available that target the lower body and advantageously emphasize highly repetitive movements coupled with low resistance. Examples include stair climbing machines, treadmills, stationary bicycles, and even devices that simulate cross country skiing. Nonetheless, although these aforementioned exercise devices are beneficial to those individuals desiring a more general aerobic workout, they are not always a feasible option to those suffering acute lower back pain.
Specifically, most of the exercise equipment mentioned above and in wide use today necessarily puts at least some measure of stress or strain on the lower back. While such a relatively low level of associated back strain is not a significant burden to the individual exercising for general aerobic conditioning, such additional strain is potentially painful or even counterproductive to those individuals exercising for rehabilitative purposes. Specifically, those persons with acute lower back pain require exercise that simultaneously provides ample aerobic benefits while minimizing the stress and strain placed on the lower back. As can readily be understood, exercise equipment such as stair climbers or treadmills do not adequately immobilize the lower back, and can indeed exacerbate existing lower back conditions if used improperly.
As an alternative, health clubs and fitness centers often have exercise machines specifically designed to isolate various muscle groups and body parts. For example, many clubs include leg press machines that enable the user to select an appropriate resistance according to specific needs. Users of such machines generally extend their legs in a pressing action causing a weighted platform of a chosen resistance to move. Such machines effectively isolate the lower extremities while minimizing lower back strain. In order to minimize strain during exercise, these machines have been constructed in a variety of designs that enable the user to operate the weight platform from a seated, recumbent, or even horizontal position. Although these machines have the advantage of being adaptable for strength or aerobic training by providing a wide range of resistances, their primary focus and use has been strength training. Specifically, such machines are generally configured in such a way so as to target musculature rather than connective tissues.
Another key disadvantage of using fitness center equipment for rehabilitation exercises is their relative inconvenience and inaccessibility. Specifically, many physical therapy patients may not be able to drive or might otherwise be inconveniently situated from a fitness center. Additionally, membership fees at many clubs may be economically prohibitive to many patients already facing additional medical care expenses. Although the equipment found in health clubs is generally available for home purchase, excessive cost and bulkiness of such equipment make home use of most "health club" equipment an unrealistic option.
An additional disadvantage found in the leg exercising equipment of the prior art is that most of the prior art machines require the exercise and simultaneous use of both legs in order for the apparatus to function properly. For example, cycling machines, both conventional and those designed for use in bed, require alternating movement of both legs. It can be appreciated, however, that many patients have disabilities that are best and most effectively rehabilitated by exercise of one leg at a time.
Many of the above described shortcomings are addressed in the leg exercise machine disclosed in the U.S. Pat. No. 5,279,530 to Hess, the inventor of the present invention. Specifically, the '530 patent discloses a portable leg exercising device especially adapted for lower back and lower extremity rehabilitation. This device advantageously emphasizes and targets the lower back by means of movement of pedals up a gradual incline against a resistance generated by one or more elastic cord(s). This device is, advantageously, lightweight and portable, but its use is unfortunately limited to individuals capable of exercising in a horizontal position. As should be appreciated, such a device, while overcoming several of the key disadvantages in the prior art, lacks a measure of versatility. For example, patients unable to comfortably and easily exercise in and rise from a reclined or horizontal position are not able to comfortably and effectively use this device.
Accordingly, there is a need for an improved lightweight, relatively inexpensive leg exercising apparatus that is portable and effective for treatment of lower back and lower extremity disabilities. Such a device should be capable of use for in-home physical therapy. Such a device should be capable of being used in a reclined or horizontal position by those patients confined to bed or who prefer to exercise on the floor. In addition, such a device should be versatile and readily adaptable for use by patients in a seated position so as to provide a means for meeting the general and varying needs of the patient population while also comfortably and effectively exercising a greater number of patients than did the prior art.